Hanger assembly

ABSTRACT

A hanger assembly and a method for supporting a string of tubular members in a wellhead assembly are disclosed wherein the hanger assembly is supported within the wellhead assembly by a single landing shoulder in the wellhead assembly and a seal member is independently, sealingly engaged with a portion of the string of tubular members.

BACKGROUND OF THE INVENTION 1. RELATED APPLICATION

[0001] This application claims the benefit of Provisional PatentApplication Serial No. 60/302,241, filed Jun. 29, 2001.

[0002] 2. Field of the Invention

[0003] The invention relates to a hanger assembly for supporting astring of tubular members, such as casing pipe or production tubing, ina wellhead assembly.

[0004] 3. Description of Related Art

[0005] Various types of hanger assemblies have been proposed forsupporting a string of tubular members, such as casing pipe orproduction tubing, within a wellhead used in connection with thedrilling and/or production of hydrocarbons. One type of hanger assemblyis configured so as to be supported in the wellhead assembly by at leasttwo inwardly extending landing shoulders formed in the wellheadassembly. It would be advantageous to have a hanger assembly which isconfigured so as to only require a single inwardly extending landingshoulder formed in the wellhead assembly. Additionally, because ofincreased loads and pressures to be supported and contained by thehanger assembly, improvements are necessary in prior art hangerassemblies. Furthermore, increased temperature differentials encounteredby hanger assemblies in use, such as −20° F. to 350° F., requireimproved performance of seals and other components in conventionalhanger assemblies, to resist and/or restrict damage by extrusion of theseal members used in the hanger assemblies.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is a perspective view of a hanger assembly in accordancewith the present invention;

[0007]FIG. 2 is a partial cross-sectional view taken along line 2-2 ofFIG. 1;

[0008]FIG. 3 is a partial cross-sectional view taken along line 3-3 ofFIG. 1;

[0009]FIG. 4 is a top view of a casing hanger slip bowl in accordancewith the present invention;

[0010]FIG. 5 is a partial cross-sectional view of the casing hanger slipbowl of FIG. 4 taken along line 5-5 of FIG. 4;

[0011]FIG. 6 is a top view of a casing hanger slip bowl housing inaccordance with the present invention;

[0012]FIG. 7 is a partial cross-sectional view of the casing hanger slipbowl housing of FIG. 6 taken along line 7-7 of FIG. 6;

[0013]FIG. 8 is a top view of the slips of the hanger assembly of thepresent invention;

[0014]FIG. 9 is a partial cross-sectional view of a the slips of FIG. 8,taken along line 9-9 of FIG. 8;

[0015]FIG. 10 is a top view of an upper support plate in accordance withthe present invention;

[0016]FIG. 10A is a partial cross-sectional view of the upper supportplate taken along line 10A-10A;

[0017]FIG. 11 is a partial cross-sectional view of the upper supportplate of FIG. 10 taken along line 11-11 of FIG. 10;

[0018]FIG. 12 is a top view of a lower support plate in accordance withthe present invention;

[0019]FIG. 13 is a partial cross-sectional view of the lower supportplate of FIG. 12 taken along line 13-13 of FIG. 12;

[0020]FIG. 14 is a partial cross-sectional view of an anti-extrusionring for use in the present invention;

[0021]FIG. 15 is a top view of a seal member for use in the presentinvention; and

[0022]FIG. 16 is a partial cross-sectional view of the seal member ofFIG. 15 taken along line 16-16 of FIG. 15.

[0023] While the invention will be described in connection with thepreferred embodiment, it will be understood that it is not intended tolimit the invention to that embodiment. On the contrary, it is intendedto cover all alternatives, modifications, and equivalents, as may beincluded within the spirit and the scope of the invention as defined bythe appended claims.

SUMMARY OF THE INVENTION

[0024] In accordance with the invention the foregoing advantages havebeen achieved through the present hanger assembly for use in a wellheadassembly, or system. The hanger assembly of the present invention isbelieved to be capable of supporting very high loads, and containinghigh pressures, and further is believed to be capable of being operableover wide temperature differentials, such as −20° F. to 350° F.

DETAILED DESCRIPTION OF THE INVENTION AND SPECIFIC EMBODIMENTS

[0025] With reference to FIGS. 1-3, a hanger assembly 20 in accordancewith the present invention is shown supported in a conventional wellheadhousing, or bowl, 21 (FIG. 2), and generally includes: a plurality ofslips 22 in contact with a portion of a string of tubular members 23; acasing hanger slip bowl housing, or housing 24; casing hanger slip bowl,or bowl 25; a casing hanger seal member upper support plate, or uppersupport plate, 26; a casing hanger seal member lower support plate, orlower support plate, 27; and a seal member 28.

[0026] Hanger assembly 20 is of a conventional split bowl construction,as shown at line 30 of FIG. 1, and includes a lower beveled surface 31adapted for abutting engagement with the single landing shoulder 32 ofwellhead housing, or wellhead housing bowl, 21. A plurality of capscrews 33 are illustrated disposed in openings 34 in FIG. 1; however,cap screws 33 are only used for installation purposes and when thehanger assembly 20 is disposed within wellhead housing 21 as shown inFIG. 2, the cap screws 33 have been previously removed.

[0027] Still with reference to FIGS. 1-3, it is seen that the outer wallsurface 35 of hanger assembly 20 is substantially smooth, having asubstantially cylindrical cross-sectional configuration with only onelower beveled surface 31 for abutting engagement with landing shoulder32 of wellhead housing 21. The outer wall surfaces of the casing hangerslip bowl housing 24, upper and lower support plates 26, 27, and theseal member 28, which comprise the outer wall surface 35 of hangerassembly 20, are all substantially coplanar with each other as shown inFIGS. 1 and 2. If desired the outer wall surfaces of upper and lowersupport plates 26, 27 and seal member 28 could be spaced inwardly of theouter wall surface of hanger slip bowl housing 24. Thus hanger assembly20 does not include a second beveled surface for engagement with anotherlanding shoulder formed in wellhead casing 21, as used in prior artdevices. Hanger assembly 20 may be used to support a string of tubularmembers 23, and the use of the term “string of tubular members” isintended to include both casing pipe, as well as production tubing, asare both known in the art. A plurality of cap screws, or bolts, 40 (16bolts being illustrated for illustrative purposes only), pass throughupper support plate 26, seal member 28, and lower support plate 27, andare threadedly received within the upper end of casing hanger slip bowl25, as shown in FIGS. 1, 2, and 5. Slip bowl 25 is provided with aplurality of threaded openings 41 (FIG. 5) for receipt of the bolts 40.

[0028] As seen in FIGS. 2, 3, and 7, casing hanger slip bowl housing 24includes an inwardly extending ledge portion 45, which restrainsdownward movement of slip bowl 25 within slip bowl housing 24, with agap 47 (FIGS. 2 and 3) initially provided between housing 24 and thelower end of slip bowl 25. Slip bowl 25 is provided with a reduceddiameter portion 100 at the lower end of slip bowl 25, which provides aradial shoulder 101, which may abut ledge portion 45 of slip bowlhousing 24. Housing 24 may further have an enlarged interior diameter asshown at 46. Slip bowl housing 24 has a generally cylindricalcross-sectional configuration with an interior wall surface 48 forreceipt of the outer surface 49 of casing hanger slip bowl 25.

[0029] As shown in FIGS. 2, 3, and 9, the plurality of slips 22 have asubstantially smooth outer wall surface 50 which slopes inwardly and ismatingly received within the substantially smooth, inner wall surface 42(FIG. 5) of casing hanger slip bowl 25. The inner wall surface 51 ofslips 22 are provided with a plurality of gripping teeth 52, as areknown in the art, for engagement with the outer surface of the upper endof the string of tubular members 23. Preferably, four slip members, orslips, 22, are provided although a lesser or greater number of slipmembers can be provided as is known in the art.

[0030] As seen in FIGS. 2, 3, 10, and 11, upper support plate 26 has agenerally cylindrical, annular configuration with a plurality ofopenings 60 disposed therein for receipt of the plurality of bolts 40.Upper plate member 26 has a downwardly extending, annular shaped ridgemember 61 for engagement with a correspondingly shaped, annular groove81 (FIG. 16), formed in the upper surface of seal member 28. Lowersupport plate 27, FIGS. 12 and 13, also has a plurality of openings 70formed therein for passage therethrough of bolts 40, as well as anupwardly extending, annular shaped ridge member 72 which is matinglyreceived in a corresponding annular shaped groove 82 formed in the lowersurface of seal member 28 (FIG. 16). Similarly, seal member 28 isprovided with a plurality of openings 80 through which the correspondingnumber of cap screws, or bolts, 40 may also pass. Upper support plate26, lower support plate 27, and seal, or packing member, 28 may beformed in two or more sections to permit assembly of the hanger assembly20 about the upper end of the string of tubular members 23, as is knownin the art. Lower support plate 27 is supported upon the upper end 49 ofslip bowl housing 24 in an abutting relationship.

[0031] Seal member 28 may be made of any suitable elastomeric materialhaving the requisite strength and temperature resistance characteristicsso as to be utilized in a conventional wellhead assembly. The corners ofthe seal member 28 may be reinforced by the use of a suitableanti-extrusion material, such as kevlar rope 83. Preferably, and inparticular for high temperature conditions, an anti-extrusion ring 90(FIG. 14) is disposed about each bolt 40, overlying the openings 80formed in seal member 28. An anti-extrusion ring 90 would be disposedabout bolts 40 in engagement with the upper and lower grooved surfaces81, 82, of seal member 28, as shown in FIG. 2. Openings 60 and 80 inupper and lower support plates 26, 27 are each preferably provided witha small annular shaped, beveled, countersink, or beveled counterbore, 63(FIG. 10A), 73 (FIG. 13) for mating engagement with the tapered outersurface 91 of each extrusion ring 90. Upon an energizing force beingexerted upon upper and lower support plates 26, 27, by threading capscrews, or bolts, 40 into casing hanger slip bowl 25, the anti-extrusionrings 90 prevent the portions of seal member 28 disposed adjacentopenings 80 in seal member 28 from being extruded, or forced into,openings 60, 70, of upper and lower seal plates 26, 27.

[0032] In operation, after hanger assembly 20 is mounted about the upperend of the string of tubular members 23 and disposed within wellheadhousing 21, the weight of the string of tubular members 23 causes theslips 22 to slide downwardly within slip bowl 25. The mating innertapered surface 42 of slip bowl 25 and the outer tapered wall surface 50of slips 22 cause the gripping teeth 52 of the slips 22 to be forcedinwardly into the string of tubular members 23, as the inner diameter ofthe slip is reduced. Either simultaneously with such movement of slips22, or thereafter, a pulling force is created by threading bolts 40 intothe threaded openings 41 and the upper end of casing hanger slip bowl25, whereby the seal member 28 is activated to sealingly engage aboutthe upper end of the string of tubular members 23. The inwardlythreading of bolts 40 serves to pull the upper support plate 26 towardthe lower support plate 27, which is supported upon the upper end 49 ofslip bowl housing, thereby compressing seal member 28 and forcing theinterior surface 85 (FIG. 16) into contact with the upper outer wallsurface of the string of tubular members 23. In contrast to prior arthanger assemblies, wherein the seal member is compressed by abuttingengagement of a portion of the hanger assembly with a second landingshoulder formed in the wellhead housing, the actuation and compressionof seal member 28 of the present invention is controlled by the amountof the pulling force exerted upon the seal member 28 via the threadingof bolts 40, and the gap 47 between slip bowl housing 24 and slip bowl25 assists in controlling the energizing force upon seal member 28.

[0033] It is to be understood that the invention is not limited to theexact details of construction, operation, exact materials, or embodimentshown and described, as obvious modifications and equivalents will beapparent to one skilled in the art. Accordingly, the invention istherefore to be limited only by the scope of the claims.

We claim:
 1. A hanger assembly for use in a wellhead housing and forsupporting a string of tubular members, the hanger assembly comprising:a hanger slip bowl housing, having an upper end, a lower end, and anouter wall surface, adapted to be supported by a portion of the wellheadhousing; a hanger slip bowl, having an upper end and a lower end,disposed within the hanger slip bowl housing; at least one slip disposedwithin the hanger slip bowl and adapted for contacting a portion of thestring of tubular members; at least one seal member adapted to sealinglyengage about a portion of the string of tubular members, the at leastone seal member having an upper surface, a lower surface, and an outerwall surface, the outer wall surface being substantially coplanar withthe outer wall surface of the hanger slip bowl housing; and the hangerslip bowl housing having a substantially cylindrical cross-sectionalconfiguration with only one beveled surface provided at the lower end ofthe hanger slip bowl housing, the only one beveled surface adapted forengagement with a single mating, inwardly extending, landing shoulderprovided in the wellhead housing, whereby the wellhead housing requiresonly a single landing shoulder to support the hanger assembly and thestring of tubular members.
 2. The hanger assembly of claim 1, includinga casing hanger seal member upper support plate provided above the atleast one seal member, and a casing hanger seal member lower supportplate provided below the at least one seal member, the upper and lowersupport plates each having an outer wall surface, and the outer wallsurfaces of each support plate are substantially coplanar with the outerwall surface of the hanger slip bowl housing.
 3. The hanger assembly ofclaim 2, wherein the lower support plate is supported upon the upper endof the slip bowl housing.
 4. The hanger assembly of claim 3, wherein thelower support plate is in an abutting relationship with the upper end ofthe slip bowl housing.
 5. The hanger assembly of claim 2, wherein theupper and lower support plates and the at least one seal member are eachprovided with at least one opening, the at least one opening of each ofthe upper and lower support plates and the at least one seal member,mating with adjacent openings to provide at least one passageway,through which each at least one passageway a bolt is passed; the bolthaving an end threadedly received within the hanger assembly, wherebyupon the bolt being threaded into the hanger assembly, the at least oneseal member is compressed into sealing engagement about a portion of thestring of tubular members.
 6. The hanger assembly of claim 5, whereinthe bolt has an upper end and a lower end, the upper end being receivedwithin the upper support plate, and the lower end is threadedly receivedwithin the hanger assembly.
 7. The hanger assembly of claim 6, whereinthe lower end of the bolt is threadedly received within the upper end ofthe hanger slip bowl.
 8. The hanger assembly of claim 1, wherein thehanger slip bowl housing has an interior wall surface and the hangerslip bowl has an outer wall surface, and a portion of the outer wallsurface of the hanger slip bowl is in sliding engagement with a portionof the interior wall surface of the hanger slip bowl housing.
 9. Thehanger assembly of claim 8, wherein the lower end of the hanger slipbowl housing has an inwardly extending ledge portion which restrainsdownward movement of the hanger slip bowl within hanger slip bowlhousing.
 10. The hanger assembly of claim 9, wherein the lower end ofthe hanger slip bowl has a reduced diameter portion which provides aradial shoulder formed in the outer wall surface of the hanger slipbowl, whereby downward movement of the hanger slip bowl within hangerslip bowl housing is restrained by the radial shoulder abutting theledge portion of the hanger slip bowl housing.
 11. The hanger assemblyof claim 5 wherein an anti-extrusion ring is disposed about each bolt,and the anti-extrusion ring overlies each of the at least one openingsformed in the at least one seal member.
 12. The hanger assembly of claim11, wherein two anti-extrusion ring are disposed about each bolt with ananti-extrusion ring in engagement with the upper surface of the at leastone seal member and an anti-extrusion ring is in engagement with thelower surface of the at least one seal member.
 13. The hanger assemblyof claim 2, wherein the upper and lower support plates each have annularshaped ridge member which are matingly received by corresponding annularshaped grooves found in the upper and lower surfaces of the at least oneseal member.
 14. The casing hanger of claim 1, wherein downward movementof the string of tubular members within hanger slip bowl does notautomatically cause compression of the at one least seal member.
 15. Amethod for supporting a string of tubular members in a wellhead assemblyhaving at least one landing shoulder, comprising the steps of: providinga hanger assembly having a hanger slip bowl housing with an outer wallsurface, a hanger slip bowl, at least one slip disposed within thehanger slip bowl, and at least one seal member with an outer wallsurface; disposing a portion of the string of tubular members within thehanger assembly; disposing and supporting the hanger assembly within thewellhead assembly by placing the hanger assembly in abutting engagementwith only one landing shoulder of the wellhead assembly; permittingdownward movement of the at least one slip member within the hanger slipbowl to cause the at least one slip member to be forced inwardly to gripa portion of the string of tubular members; and compressing the at leastone seal member by exerting a compressive force upon the at least oneseal member to cause it to sealingly engage about a portion of thestring of tubular members.
 16. The method of claim 15, wherein thecompressive force to the at least one seal member is provided bythreading at least one bolt into the hanger assembly, the bolt beingoperatively associated with the at least one seal member.
 17. The methodof claim 16, including the step of associating at least oneanti-extrusion ring with the at least one bolt.
 18. The method of claim15, including the step of disposing the outer wall surfaces of thehanger slip bowl housing and the at least one seal member substantiallyco-planar to each other.